Related papers: Interacting compact binaries: modeling mass transf…
Context: The principal mechanism by which brown dwarfs form, and its relation to the formation of higher-mass (i.e. hydrogen-burning) stars, is poorly understood. Aims: We advocate a new model for the formation of brown dwarfs. Methods: In…
We present in this contribution our set of multiwavelength synthesis models including the evolution of single and binary stars. The main results we have obtained can be summarized as follows: (a) massive close-binary systems will start to…
Most subdwarf B (sdB) + Helium white dwarf (He WD) binaries are believed to be formed from a particular channel. In this channel, the He WDs are produced first from red giants (RGs) with degenerate cores via stable mass transfer and sdB…
Since their initial discovery, the origin of isolated white dwarfs (WDs) with magnetic fields in excess of $\sim$1 MG has remained a mystery. Recently, the formation of these high-field magnetic WDs has been observationally linked to strong…
The formation of neutron stars (NSs), both from collapses of massive stars and mergers of compact objects, can be usually indicated by bright transients emitted from explosively-ejected material. In particular, if the newborn NSs can rotate…
Some binary systems composed of a white dwarf (WD) and a hot subdwarf (sdB) helium star will make contact within the helium burning lifetime of the sdB star. The accreted helium on the WD inevitably undergoes a thermonuclear instability,…
Context: Subdwarf B stars (sdBs) play a crucial role in stellar evolution, asteroseismology, and far-UV radiation of early-type galaxies, and have been intensively studied with observation and theory. It has theoretically been predicted…
We study mass ejection from accretion disks formed in the merger of a white dwarf with a neutron star or black hole. These disks are mostly radiatively-inefficient and support nuclear fusion reactions, with ensuing outflows and…
Close interactions and mass transfer in binary stars can lead to the formation of many different exotic stellar populations, but detailed modeling of mass transfer is a computationally challenging problem. Here, we present an alternate…
We report on an undergraduate student project initiated in the summer semester of 2004 with the aim to establish equations of state for white dwarfs and neutron stars for computing mass-radius relations as well as corresponding maximum…
We investigated the statistical properties of both cool and hot starspots in eclipsing binary stars. The starspot and binary parameters for contact and semi-detached systems were collected from literature, which were determined on the basis…
We study the final stages of the evolution of a binary system consisted of a black hole and a white dwarf star. We implement the quantum hydrodynamic equations and carry out numerical simulations. As a model of a white dwarf star, we…
Gamma-ray bursts are characterized by a duration of milliseconds to several minutes in which an enormous amount of radiation is emitted. The origin of these phenomena is still unknown because proposed models fail to explain all the observed…
Motivated by suggestions that binaries with almost equal-mass components ("twins") play an important role in the formation of double neutron stars and may be rather abundant among binaries, we study the stability of synchronized close and…
Asteroid material is detected in white dwarfs (WDs) as atmospheric pollution by metals, in the form of gas/dust discs, or in photometric transits. Within the current paradigm, minor bodies need to be scattered, most likely by planets, into…
Multi-messenger observations of binary neutron star mergers provide a unique opportunity to constrain the dense-matter equation of state. Although it is known from quantum chromodynamics that hadronic matter will undergo a phase transition…
We elaborate on the analytical model of Ritter, Zhang, and Kolb (2000, A&A 360, 959) which describes the basic physics of irradiation-driven mass transfer cycles in semi-detached compact binary systems. In particular, we take into account a…
The formation and evolution of binaries which contain two neutron stars or a neutron star with a black hole are discussed in detail. The evolution of the distributions in orbital period and eccentricity for neutron star binaries are studied…
The majority of stars both host planetary systems and evolve into a white dwarf (WD). To understand their post-main-sequence (PMS) planetary system evolution, we present a search for transiting/eclipsing planets and other Substellar Bodies…
We use a variety of visualization techniques to display the interior and surface flows in a double white dwarf binary undergoing direct-impact mass transfer and evolving dynamically to a merger. The structure of the flow can be interpreted…